If we accept the premise “the focus of Lean is the identification and elimination of waste” then I would argue that most Application Support activities are an example of Waste that should be eliminated.
Support is a manual intervention activity. The amount of support required by an application is directly related to the failure of the development team to design the Application to minimize support by including sufficient data validation, self-correction, and user controlled logic via parameters.
Lean Application Support should enhance the application to eliminate support.
Lean development should create applications that require minimal support.